Direct current timer

ABSTRACT

An automatic timing circuit for controlling a pump solenoid valve or other device which may be adjusted over a wide range of cycles per hour and which may be manually energized if desired.

United States Patent Roberts [4 1 7 Mar. 28, 1972 s41 DIRECT CURRENTTIMER 3,449,595 6/1969 Marek ..3o7/2s2 1 3,392,626 7/1968 Miller et a1...307/252 B [721 Rams ohm 3,309,535 3/1967 Sutherland et al. ..307/2s2K [73] Assignee: Houdaille Industries, Inc., Buffalo, N .Y.

OTHER PUBLICATIONS [22] Filed: July 1, 1970 G. E. SCR Manual 4th Edinon,1967; p. 153 (Fig. 8.13), 165 12 1 pp NM 51,567 (Fig. 8.26), 166, 199(Fig, 9.33

52 us. c1. ..307/252 M, 307/252 w, 307/284, Primal? Examiner-DonaldFor!" 307 293 Assistant Examiner-L. N. Anagnos 511 1111. (:1. ..H03k17/28, H03k 17/30, 11031; 17/72 Attorney-Hill, Sherman, Mewni, Gross andSimpson [581' Field of Search ..307/252 B, 252 G, 252 .l, 252 K,

307/252 L, 252 M, 284, 293, 305 RACT An automatic timing circuit forcontrolling a pump solenoid [56] References cited valve or other devicewhich may be adjusted over a wide range UNITED STATES PATENTS of cyclesper hour and which may be manually energized if desired. 3,349,38610/1967 Zug ..307/293 X 3,353,032 11/1967 Morgan et a1. ..307/252 B 2Claims, 1 Drawing Figure D I /Z 2/ I m 2; 11 w

1. A circuit for controlling the application of power to a load from apower circuit comprising: a first silicon controlled rectifier with itsanode and cathode connected in series with said load and said powersupply; a first capacitor connected between said power supply and thegate of said first silicon controlled rectifier; a second siliconcontrolled rectifier with its cathode connected to the cathode of thefirst silicon controlled rectifier; a second capacitor connected betweenthe anodes of said first and second silicon controlled rectifiers; afirst resistor connected between said anode of said second siliconcontrolled rectifier and one terminal of said power supply; a firstunijunction transistor with a first base connected to the gate of saidsecond silicon controlled rectifier; a second resistor connected betweensaid gate and cathode of said second silicon controlled rectifier; athird capacitor connected between said cathode of said second siliconcontrolled rectifier and the emitter of said first unijunctiontransistor; a third resistor connected between the emitter of said firstunijunction transistor and the anode of said second silicon controlledrectifier; a fourth resistor connected from the second base of saidfirst unijunction transistor and the anode of said second siliconcontrolled rectifier; a second unijunction transistor connected acrosssaid power supplied with a first base connected to the gate of the firstsilicon controlled rectifier; a fourth capacitor connected between thesecond side of the power supply and the emitter of said secondunijunction transistor; a plurality of timing resistors with first sidesconnected to the emitter of said second unijunction transistor; switchmeans connected to one side of the power supply and engageable with oneof said timing resistors; a third unijunction transistor with its basesconnected across said power supply; a fifth capacitor connected betweenthe emitter of said third unijunction transistor and the second side ofthe power supply; and a sixth capacitor connected between the emitter ofthe third unijunction transistor and the second base of said secondunijunction transistor.
 2. A circuit according to claim 1 comprising amanual switch connected between the anode and cathode of said firstsilicon controlled rectifier.